Temperature Dependent Mechanical and Structural Properties of Uniaxially Strained Planar Graphene

TL;DR

This study uses molecular dynamics simulations to analyze how temperature affects the mechanical and structural properties of uniaxially strained planar graphene, revealing linear trends in elastic parameters and detailed bond distributions.

Contribution

It provides the first detailed analysis of bond length and angle distributions in strained graphene as functions of temperature and strain.

Findings

Young's modulus decreases linearly with temperature

Fracture stress and strain decrease with temperature

Bond length and angle distributions are characterized and modeled

Abstract

Using molecular dynamics simulations in a planar graphene sheet, we investigate the temperature dependence of its mechanical behavior under uniaxial tensile stress applied either along the armchair or the zigzag direction. Stress-strain curves are calculated for different temperatures and the corresponding dependence of various elastic parameters, is discussed. Fracture stress and strain, as well as the Young modulus, decrease almost linearly with temperature, in accordance with previous investigations. An almost linear variation of the third-order elastic modulus with temperature is demonstrated, revealing opposite trends for uniaxial loadings along the armchair or the zigzag direction. The detailed dependence of the distributions of bond lengths and bond angles both on strain and temperature is presented for the first time, along with approximate analytical expressions. The latter describe accurately the numerically obtained distributions.